shogi and artificial intelligence - discuss japan-japan ... · 07/04/2003 · that “the...
TRANSCRIPT
Discuss Japan—Japan Foreign Policy Forum No. 32
Shogi and Artificial Intelligence
Kamiya Matake, Professor at the National Defense Academy of Japan
In Cooperation with Professional Shogi Player Sato Yasumitsu
he waves of the third artificial intelligence
(AI) boom are now sweeping across Japan
in the same way as earlier fads did in the
1950s and the 1980s. Referring to the ongoing
craze in the country, leading Japanese economic
magazine Shukan toyo keizai wrote in its 5
December 2015 issue, “not a single day passes by
without hearing about AI.” Many companies in
Japan are making AI-related announcements one
after another. Seminars on AI are held in Tokyo
almost every day.
But the question we must ask is this: Is the
development of AI good news for mankind? From
early on, many people in the world outside Japan
forecast a dystopian future if AI were to surpass human intelligence. To cite an early example, Bill
Joy, a U.S. computer scientist dubbed the Thomas Edison of the Internet, cautioned that robots
with higher intelligence may compete with humans and threaten the latter’s survival when they
become able to self-replicate in “Why the Future Doesn’t Need Us,” an article he published in 2000.
More recently, British theoretical physicist and cosmologist Stephen Hawking expressed the fear
that “the development of full artificial intelligence could spell the end of the human race.” Speaking
in concert, Microsoft founder Bill Gates also said, “I am in the camp that is concerned about the
threat of super intelligence [to human beings].”
Behind their concern, there is the feeling of unease that humans will stop being the owners of
the highest intelligence on earth. Humans cannot match many other animals in terms of physical
abilities, such as power and speed. High intelligence is the very thing that has allowed humans to
consider themselves as special beings distinguished from other animals. What will happen if and
when AI surpasses human intelligence? Will humans really be able to continue their dominance as
rulers of the earth in this situation? Won’t machines deprive humans of many intellectual jobs and
dominate them, in effect?
Japanese Manga, Animations and AI
These arguments about the possible threats posed by AI have been small in number in Japan until
recently, however. It has been said that Japanese manga comic books and animations have affected
T
Author: KAMIYA Matake,
Professor, National
Defense Academy of
Japan
Advisor: SATO Yasumitsu,
professional shogi player
Discuss Japan—Japan Foreign Policy Forum No. 32
this tendency significantly with their depictions from early on of the bright future with active
intellectual humanoids. For example, Tezuka Osamu (1928–1989), known as “the father of
Japanese manga” and “the god of manga,” continued to draw Tetsuwan Atomu (Astro Boy), a
manga in which the boy robot Atom with a heart like that of a human works and fights energetically
for justice in the dream society of the twenty-first century, for many years from 1952. Tetsuwan
Atomu was turned into an animation, and its humanoid protagonist became a hero among
Japanese children in the period of high economic growth. (The animation was also broadcast
overseas under the title Astro Boy.) Many AI and robot researchers and engineers working
successfully in Japan today say that they chose their career due to the wish to make their dream of
creating Atom come true. Tezuka set 7 April 2003 as Atom’s birthday. To commemorate this date,
the Journal of the Japanese Society for Artificial Intelligence ran a special feature on Atom in its
issue dated March 2003. In another manga, Doraemon, which Fujiko F. Fujio (1933–1996) kept
producing from 1970 until just before his death, a robot called Doraemon (also with a heart and
feelings, just like humans) that travelled from the twenty-second century to the twentieth century
lives with Nobita, an elementary school boy who is not good at studies, sports or just about
everything else, and helps Nobita as his best friend. The animated version of Doraemon is still
broadcast on television every week. The animation continues to fascinate many children, not only
in Japan but also in other countries in East Asia.
Atom and Doraemon are new friends for humans that were created with the science and
technology of the future. They never harm humans. They cooperate with humans and try to offer
them service. In the meantime, humans do not discriminate against them, and treat them as their
associates. This view of robots has symbolized the positive impressions of AI that the great majority
of Japanese people have had.
Shogi: A traditional shogi board with a set of shogi pieces in the starting setup. The
stands on both sides of the board are used to hold captured pieces.
COURTESY OF JAPAN SHOGI ASSOCIATION
Discuss Japan—Japan Foreign Policy Forum No. 32
However, this situation has begun to change. The changes have been particularly noticeable
since the spring of 2013. What limitless AI development will bring to humans has suddenly become
an issue that is frequently discussed with a mixed sense of expectation and unease in Japanese
society, too, in the midst of the AI boom described at the start of this article. What on earth was it
that happened in Japan in the spring of 2013? What was it that caused the Japanese people’s
attitude toward AI to change suddenly around that time?
It was neither a great scientist like Professor Hawking nor a prominent entrepreneur like Bill
Gates. It was a board game native to Japan called shogi that caused this change. This must be an
answer that puzzles most readers overseas. What is shogi in the first place? Why did it shake the
Japanese people’s attitude toward AI? How can one board game have such a major influence on
Japanese society?
Shogi is a Japanese version of chess. A board game called chaturanga that was played in ancient
India spread to various parts of the world and branched out into games with original pieces and
rules in the respective regions. Chaturanga changed into chess in the West, xiangqi in China and
shogi in Japan. Shogi is a game that has been played widely among Japanese people, regardless of
their class or financial standing, since around the sixteenth century when the current rules were
established. Shogi remains popular today, with the playing population (the number of people who
play shogi at least once each year) estimated at about 10 million among the total Japanese
population of approximately 127 million.
The Den-osen Shock – Shogi as a Traditional Japanese Culture under Challenge
One historic series of shogi matches drew widespread public attention in Japan from March to
April 2013. Five software programs that won in a shogi tournament for computer software in the
previous year played against five professional shogi players in this series called Den-osen
(Electronic King Championship). Against the odds, the software programs won overwhelmingly
against the humans in these first serious shogi matches between humans and computer programs.
The programs ended the series with a record of three wins, one loss and one draw. Major television
stations, newspapers, magazines, Internet news sites and other media in Japan extensively
reported the news that computer programs had beaten human professionals in the game of shogi.
The news gave Japanese people a substantial shock. Following the historic shogi match series, the
Japan Broadcasting Corporation (NHK) televised a special program titled, “AI Outperforming
Humans May be the Strongest in the World.” The human defeat in Den-osen made most Japanese
people aware for the first time of the hard reality that, through continued development, AI was
beginning to drag humans down from the leading role in intellectual activities that had been seen
as revolving around them as a matter of course.
We suspect that even this explanation doesn’t make sense to many readers overseas. Shogi may
be popular in Japan, but it’s only a game. Besides, in the world of chess, Deep Blue, a chess-playing
computer developed by IBM, had defeated a human world champion sixteen years earlier, in 1997.
Why on earth was the victory of computer programs over humans in the Japanese chess equivalent
so significant after all those years?
To understand this point, readers overseas must understand that shogi is more than a game in
Japan, and that it has been historically regarded as constituting part of traditional Japanese culture
Discuss Japan—Japan Foreign Policy Forum No. 32
alongside the tea ceremony (sado) and Japanese flower arranging (ikebana). In the Edo period
(1603–1867), the Tokugawa shogunate protected shogi and go, another traditional board game
played in Japan. The shogunate paid the respective iemotos, or families heading game schools
(three families for shogi and four families for go), a yearly allowance and urged them to compete
against each other in terms of playing skills. Top shogi players centered on those from the three
iemoto families were provided with an honorable opportunity to face each other across the board
and demonstrate the results of their day-to-day studies in Edo Castle in the presence of the shogun
every year in the lunar month of November. The shogun sometimes spoke to them directly on these
occasions. (Top go players played matches in the presence of the shogun in the same way.)
There are countless parlor games around the world. From way back, many people have
attempted to make a living by playing them. In the past, society usually viewed these people as
gamblers. However, top shogi and go players in the Edo period were viewed differently. They were
professionals who were officially recognized and salaried by the government of their time. Society
showed them respect. From a global point of view, it was rare for such a system of professional
game players to become established at this early a point. Its establishment shows that the
Tokugawa shogunate considered shogi and go as cultures that it should develop.
Alongside go, shogi is widely recognized as a traditional Japanese culture in Japanese society
today. People who have read Japanese newspapers must be aware that shogi and go columns
appear in almost all of them every day. Speaking of shogi, there are currently approximately 200
professional players and about fifteen tournaments offering prizes in Japan. (In addition, there are
several shogi tournaments open to female professionals only.) Parties such as newspapers, other
media organizations, private companies and local governments sponsor almost all of these
tournaments. With the exception of those that are televised, matches between professional shogi
players usually take a whole day. In some cases, they continue for two days. One full year is spent
on the majority of shogi tournaments for that reason. The respective newspapers cover the record
of each shogi match in a self-sponsored tournament with an observer’s account written by an expert
reporter over a period of several days.
Professional Shogi Players as Super Brains
The professional shogi players who win these tournaments, particularly the seven major ones,
earn substantial prize money (42 million yen in the top-prize tournament). They are also treated
as persons of distinction in Japanese society. For these reasons, many children and young people
dream of becoming professional shogi players. The road to this career is extremely difficult to travel,
though.
People who wish to become professional shogi players must “graduate” from the Shoreikai, an
organization for training professional players operated by the Japan Shogi Association (Shoreikai
means a society to encourage future players). Would-be professional shogi players usually join this
organization in their elementary school days, or in junior high school at the latest. These hopefuls
have the shogi-playing ability of the top amateur class at this point. They are children considered
shogi geniuses in their respective local neighborhoods, because they have almost no rivals even
among the elders. To obtain permission to join the Shoreikai, these hopefuls must achieve results
above a certain level in matches against such strong peers and produce a score above a certain level
Discuss Japan—Japan Foreign Policy Forum No. 32
in test matches against members of the Shoreikai. Accordingly, it is not easy to clear the first hurdle
of joining the Shoreikai. About 70 to 100 would-be professionals undergo examinations to join the
Shoreikai every year. Only about twenty of them pass.
Professional players SATO Yasumitsu (left) and HABU Yoshiharu compete in the final best-of-seven games
series in one of the major professional shogi tournaments.
COURTESY OF JAPAN SHOGI ASSOCIATION
What is more, the Shoreikai is many times more difficult to graduate from than to join. The
Shoreikai members play matches at ten levels, according to their ability. They are promoted or
demoted according to the match results. New members are initially assigned to the second-lowest
level. It takes them several years to more than a decade to reach the highest level from there. Only
about one-fifth of hopefuls who join the Shoreikai survive and reach the top level. And then there
is the final obstacle awaiting those who have managed to reach the highest level. Shoreikai
members at this level play shogi in incomplete round-robin tournaments (each member who
belongs to the top level plays eighteen games with different opponents preassigned at the start of
the tournament) for six months twice each year. Only those members who finish this incomplete
round robin in first and second places are allowed to become professional players. Those members
who fail to become professionals before their 26th birthday must leave the Shoreikai, in principle.
The Shoreikai had 160 members at the end of 2015, but only thirty of them belonged to the highest
level. According to past statistics, only one half to two-thirds of them will become professionals. In
other words, only about 10% to 15% of hopefuls who find their way into the Shoreikai are able to
turn professional.
The intensity of the battles within the Shoreikai is well known in Japanese society. On 9 March
Discuss Japan—Japan Foreign Policy Forum No. 32
2014, Japanese newspapers reported in unison that Miyamoto Hiroshi, then 28, had gained his
promotion to the rank of a professional shogi player by winning the final match in the Shoreikai’s
top league. Why did the promotion of this obscure young man to the rank of professional become
nationwide news? The fact is that the Shoreikai has an extra-time rule, which permits members
who are over 26 years old to compete in the top league on the following occasion in cases where
they post more wins than losses. Miyamoto had narrowly escaped membership withdrawal by
posting more wins than losses in three consecutive incomplete round robin after surpassing the
age limit of 26. In particular, in the incomplete round robin immediately before his promotion,
which ran from April to September 2013, Miyamoto had a record of nine wins to eight losses at the
point where he was about to go into the last match. He would be able to remain in the league if he
won this last match and posted ten wins to eight losses. But by losing this match, he would also be
forced to leave the Shoreikai. This is the situation that existed for Miyamoto. As a matter of fact,
Miyamoto’s opponent in this crucial match was also 26 years old. This player came into the match
with exactly the same record of nine wins to eight losses. In other words, this match was an
unprecedented, eleventh-hour battle for both of these two hopefuls. Losing the match meant the
end of the dream of becoming a professional for both of them. Miyamoto won the duel. He finally
gained the qualifications to become a professional by finishing the following incomplete round
robin, which was played from October 2013 to March 2014, in second place. The final match in this
incomplete round robin was as ruthless as the last match in the previous one. Both Miyamoto and
his opponent went into the match with twelve wins to five losses. They knew they would finish in
second place if they won this last one. In other words, they were in a situation where only the
winner could gain the status of a professional, which they had both chased for many years since
childhood. Miyamoto won this decisive contest again.
Miyamoto, a contender who had survived by winning competitions against many boy wonders
and girl wonders up to that point, made his dream come true at long last by enduring his battle
with the age limit and winning the two life-or-death showdowns. Japanese people know what that
means. Many TV programs and books produced in the past depicted the anguish of young people
who failed to make it through the Shoreikai and become professionals, and have attracted
considerable public attention. That is why the dramatic promotion of an unknown shogi player
called Miyamoto became nationwide news in Japan.
People in Japan recognize about 200 shogi players who have overcome such competition within
the Shoreikai and become professionals (only the top 0.00002% of approximately 10 million shogi
players in Japan) as super brains, because the competition they undergo is so cruel. Computer
software programs beat those supermen, though. The beaten professional shogi players included
two top rankers who had won tournaments for professionals. The computer victories were no
accident that occurred just once. In the second Den-osen series, played from February to April
2014, computer programs beat human professionals again with a record of four wins to one loss.
Dwango Co., the Den-osen sponsor, broadcast all the matches in the second Den-osen series live
on Niconico Douga, a leading video-sharing website in Japan under its operation. The number of
people who watched at least one of those five matches on Niconico Douga totaled more than
2,130,000 in 2014. A large number of Japanese people, including those who are not shogi
enthusiasts, witnessed how a computer software program could crush a human professional on a
real-time basis and experienced a shock.
Discuss Japan—Japan Foreign Policy Forum No. 32
Rapid Development of Computer Shogi Software
To be sure, Japanese people knew that computers had grown stronger than humans in chess long
before. However, Japanese people, particularly those who are enthusiastic about shogi, thought
that computers would overtake humans in shogi only in the distant future, if they did so at all,
because shogi is a game that is far more complex than chess. A shogi board has nine squares
lengthwise and crosswise. It is larger than a chessboard, which has eight squares vertically and
horizontally. Furthermore, forty pieces of eight types are used in shogi, compared with thirty-two
pieces of six types employed in chess. And there is a rule peculiar to shogi that is not found in chess
or other similar board games originating from chaturanga and played in countries around the
world, including xiangqi. This rule allows players to use captured pieces. Shogi players keep the
pieces taken from their opponent off-board as their reserve pieces. They can place such piece in a
board position of their choice and start using the piece as their own when their turn to make a move
comes. For this reason, a shogi match takes about 110 moves to finish on average, compared with
the average number of chess moves of about 80 per match. Game-tree complexity (the number of
possible games) for chess is 10123. The complexity for shogi is 10226.
The development of computer shogi programs ran into trouble because of this complexity. The
development of the first computer system for playing shogi commenced in 1974. At the beginning,
it was difficult to write a program that was able to finish a match without violating the rules. Many
engineers began to publish a variety of computer shogi programs in the second half of the 1980s.
Some of them were turned into products such as Famicom game software programs. However, the
growth of their playing skills was slow compared with computer chess programs. Computer shogi
programs were still weaker than the best human amateurs toward the end of the 1990s, when
computers overtook humans in the world of chess. Observers were able to say with absolute
certainty that computer programs had no chance of victory against professional shogi players. This
situation continued.
Game Board Size Number of
Pieces
Number of Different
Pieces
Game-Tree Complexity
(Number of
Possible Games)
Average Game Length
Shogi 9 x 9 40 8 10226 110 moves
Chess 8 x 8 32 6 10123 80 moves
It was around 2005 when this barrier was overcome and software programs that were able to
beat professional shogi players from time to time finally appeared. Several years later, computer
shogi programs achieved an evolution that was even more remarkable. At a press conference held
after the completion of the fifth match in the 2014 Den-osen series, Tanigawa Koji, the president
of the Japan Shogi Association who had won twenty-seven major tournaments (the fourth highest
number in history), was forced to say, “I must admit that strong software programs today have
more ability than middle-ranked professionals.” We can easily share the feelings of Tanigawa, who
Discuss Japan—Japan Foreign Policy Forum No. 32
had to make such a remark as a top leader in shogi circles. However, even this statement might
have been too sympathetic to humans. Without exception, computer shogi program researchers
and developers have stated their views that are more pessimistic about humans. Professor
Takizawa Takenobu of Waseda University, who serves as the president of the Computer Shogi
Association, has the opinion that human shogi players are no longer competitors for computer
software programs, with the exception of a handful of the strongest professionals. Answering my
question, Takizawa hesitantly shared his forecast that shogi software programs would probably
surpass the strongest human player in ability in two to three years. Professor Matsubara Hitoshi
of Future University Hakodate, who acts as the president of the Japanese Society for Artificial
Intelligence, takes a view that is even more merciless. Matsubara stresses the point that even the
strongest human professional rarely finishes a shogi match without making a wrong move, but a
computer program never makes a mistake even though it may have a bug. For that reason,
Matsubara takes the view that humans have been driven into a corner where they no longer have
any alternative but to look for a bug in order to compete with a software program.
Are Samurais on the Verge of Death?
Many professional players also take the view that computer shogi programs have started to
threaten even top professionals. Kawaguchi Toshihiko, a professional player-turned-writer known
for many books on shogi and respected among shogi enthusiasts as a storyteller who is able to share
episodes from the world of professional shogi, told me the following in April 2014. (Kawaguchi
passed away in January 2015). “I wonder . . . the four exceptionally strong players are likely the
only human players today who are able to compete with computer (shogi) programs.” Kawaguchi
stared at the display of a laptop computer in front of him with his head tilted to one side for a while
after making the following statement: “I mean Habu Yoshiharu (who has won 94 major
tournaments, the largest number in history), Watanabe Akira (who has won 17 such tournaments,
the sixth largest number in history), Sato Yasumitsu (who has won 13 such tournaments, the
seventh largest number in history, and Moriuchi Toshiyuki (who has won 12 such tournaments,
the eighth largest number in history). Who else (can beat computer programs) aside from those
four, I wonder?” The laptop display in front of us showed the fourth match in the Den-osen series
played that year, in which a computer software program called Tsutsukana was beginning to crush
Morishita Taku, a shogi player who had won eight professional tournaments and finished six major
ones in second place. We were visiting Odawara Castle to watch this match. Odawara Castle is
representative of Japanese castles built in the Edo period (1603–1867). It is located about a 30-
minute Shinkansen (bullet train) ride from Tokyo. The venue for the match was set in this castle in
a special arrangement for the occasion to bolster the image that shogi is a traditional Japanese
culture. After following the match on the display for some time, Kawaguchi opened his mouth again
and added quietly but with feeling, “They will become unable to beat the computer programs one
of these days, but I hope they will delay the arrival of this time as much as they can.”
Katsumata Kiyokazu, a middle-ranked professional shogi player who had taken note of
computer shogi programs since their early phase, has continued his studies and acts as a visiting
professor at the University of Tokyo today, takes an even harsher view. At Odawara Castle,
Katsumata said to me in a matter-of-fact tone, “I think that computer programs have practically
Discuss Japan—Japan Foreign Policy Forum No. 32
surpassed humans.” In reply to my question as to what he meant by the word “practically,”
Katsumata confidently said, “I can no longer beat computer programs. But I think that Habu, the
strongest human player, could beat all the programs if he did something like taking leave from all
matches for one year and studying specific software programs. I think Sato, who is here today,
could also beat the programs if he did something like that. (Sato Yasumitsu brought the author to
this venue, which was off-limits to people who had nothing to do with the match.) But I don’t think
they can do things like that.”
MORISHITA Taku competes in the fourth match in the 2014 Den-osen series against the computer software
program Tsutsukana.
COURTESY OF JAPAN SHOGI ASSOCIATION
The Niconico Douga video-sharing site circulated the following message at the beginning of the
live webcast of the fifth Den-osen match played one week later.
The world until yesterday and the world from today
What has changed and what has remained unchanged?
[Omission here]
What we are watching is a show that forces the samurais who survive in this modern age to
face the latest weapons and die a noble death in the battlefield in a manner befitting warriors
(meaning graciously and beautifully).
In this match, a computer software program called Ponanza beat Yashiki Nobuyuki, a strong
professional shogi player ranked tenth who had three career major tournament victories at that
point. Access counts for the Niconico Douga live webcast of the match surpassed 630,000. The
news that human players had won only two of ten matches played against computer programs in
the past two years (with one draw) flew about in the mass media after Yashiki’s defeat. Computers
have demonstrated their amazing ability in an area of traditional Japanese culture. They are
beginning to overwhelm flesh-and-blood super intellectuals. Readers who have read this far in this
article should now understand how great this shock was to Japanese people. In this way, shogi
became a cause for Japanese people to feel uneasy about the possibility that AI may force humans
out of their position as the beings with the highest intelligence on earth with its continued evolution,
in the same way that Joy and Hawking did.
Discuss Japan—Japan Foreign Policy Forum No. 32
Will There Be a Human Counteroffensive?
Will machines called computers deprive professionals called shogi players of the reason for their
existence in the not-too-distant future? Surprisingly, few people, including professional players,
computer shogi program researchers and their developers, appear to think that way yet, at least at
this point.
To begin with, many professional shogi players think that humans lose to computer programs
because they make mistakes. They believe that humans can compete with software programs
sufficiently in terms of their ability to make predictions. For example, Sato Yasumitsu said he
received the impression that computer programs beat human professionals in the Den-osen series
of matches by taking advantage of human weaknesses. In other words, professional shogi players
lost many matches against computer programs by making thoughtless mistakes after developing a
favorable position for a period. Computers win matches against humans because humans make
mistakes. Looking at it from the opposing direction, Sato suggests that humans would shape their
positions better than computer programs if there were no mistakes.
From this point of view, Morishita Taku, a professional player who had lost to Tsutsukana at
Odawara Castle, raised an issue and pointed out the need for special rules for matches between
humans and computer programs. Looking back on the lost match with a positive attitude,
Morishita said, “It was an extremely good opportunity for me, and it reignited my passion for shogi
after a long time. It was wonderfully productive.” At the same time, however, Morishita asserted
that it was not fair to apply exactly the same rules for human-to-human matches to clashes between
humans who unavoidably make errors and computer programs that make no mistakes whatsoever.
A player loses everything in a shogi match by making a single mistake after ninety-nine great moves.
Accordingly, special rules that minimize the chances of human error are necessary for determining
whether humans or computer programs have shogi-playing skills that are purely higher in level.
That was Morishita’s opinion. His specific proposal was to supply human players with a shogi
board and a complete set of pieces separately from those used in the match for studying moves,
and to sufficiently extend the time limit for considering the next move. Explaining that he made
almost no mistakes in practice matches using the separate board and pieces under a rule of 15
minutes allowed per move, Morishita stated confidently that strong professional players would be
able to beat computer shogi programs under those conditions.
Nine months later, Morishita proved in person that there were grounds for his confidence.
Morishita was granted an opportunity to face Tsutsukana, the program that had beaten him nine
months earlier (its updated version, to be precise), again from December 31, 2014 to January 1,
2015 under the rules he had proposed, with the exception of a slightly shorter time limit of ten
minutes per move. The Niconico Douga site webcast this match live again. The match was
suspended about twenty hours after it started in consideration for human fatigue, because the
extended time limit caused it to run for too long. Morishita stunned the people who were watching
the match on the Net by not making any thoughtless moves. Morishita dominated Tsutsukana on
the board from early on. He gradually solidified his dominance to the point of building a position
that made his victory almost certain at the point of the match suspension.
Not all professional shogi players support Morishita’s proposal of allowing humans to use a
Discuss Japan—Japan Foreign Policy Forum No. 32
separate board and pieces for considering moves, however. “I think that shogi was originally
designed to be played in the head only,” said Sato. “I grew up listening to my teachers, who said
that we cannot improve our playing skills by thinking about how to move pieces by actually moving
them on the board. That’s not training, they said. Accordingly, I am resistant to the idea of
considering moves using a separate board and pieces.”
Many professional shogi players appear to feel the same way as Sato. The Japan Shogi
Association has not adopted the rules proposed by Morishita in subsequent matches between
humans and computer programs. However, there is no doubt that Morishita proved with his own
ability the correctness of his theory that humans are not inferior to computer programs when
human error is eliminated.
In the meantime, another group of professional shogi players emerged. They focus on the point
that computer programs are error-free, but that they have bugs. In the Den-osen Final series played
from March to April 2015, two professional shogi players beat software programs by taking aim at
their bugs. On the team level, humans beat computer programs for the first time, too, posting three
wins to two losses. In the Den-osen series, computer software updates are prohibited about three
months before each match. The latest versions of the software programs at that point are supplied
to humans for advance studies. These studies enabled professional shogi players to discover any
bugs before the 2015 Den-osen series.
There is criticism that this approach to playing shogi goes against the essence of the board game.
To cite an example, the Nihon keizai shimbun newspaper wrote, “It is difficult to align the aesthetic
sense that professionals are those who fascinate viewers with the gambler-like attitude of thinking
only about victories.” Sato also said, “I don’t want to do things like searching for bugs.” However,
Katsumata is positive. Katsumata said, “We began to get to know the habits and weaknesses of
computer software programs thanks to the experience we accumulated through the last three series
of matches against them.” The Sankei shimbun newspaper called the attitude of professional
players who “dared to make bad moves outside tesuji (sequence of the best moves) and invited
computer programs to function irregularly” by “studying their habits and blind spots exhaustively”
a “type of tenacious guerrilla tactics.”
Takizawa, who has spent more than forty years developing a shogi software program that is
able to beat humans, said that the Den-osen Final was a series of “matches typical of those played
between humans and computer programs.” Takizawa provided the following explanation:
“Professional shogi players thoroughly studied computer programs’ playing logic and attacked
their weaknesses. They showed that humans can beat computer programs depending on how they
play, although they are no match for the programs in terms of simple prediction depth.” Takizawa
then said, “Matches against humans will remain extremely meaningful, because computer
programs can work out countermoves when weaknesses are found in this way.”
Takizawa’s words express the heartfelt respect he feels for the strength displayed by
professional shogi players. Shogi professionals have splendid abilities and skills. Their losses to
computer software programs do not tarnish their value. I talked to numerous computer shogi
researchers and developers to prepare myself for this contribution. Many of those people told me
the same thing. For example, Takeuchi Akira, the developer of Shueso, a computer shogi program
that beat one of the professional players and won the title of MVP in the 2014 Den-osen series,
replied promptly as follows when I asked him when computer programs would surpass humans:
Discuss Japan—Japan Foreign Policy Forum No. 32
“I don’t think computer programs have surpassed humans even at the point where they begin to
beat professional shogi players.” Takeuchi said that he finds that there is a lack of sensibility in
shogi played by computer programs compared to shogi played by humans. For example,
professional shogi players seek a victory, but, at the same time, they want to make their victory the
outcome of beautiful shogi or a well-played game, if doing so is at all possible. “Machines do not
have such sensibility,” pointed out Takeuchi. “My goal has been and will always be to develop a
software program that achieves this style of shogi.” Takeuchi added that professional shogi players
might be able to discover “depth not previously found in shogi” by joining forces with computer
programs.
In the meantime, professional shogi players pay candid respect to the evolution of computer
shogi programs and also acknowledge their strength. For example, Toyama Yusuke, a professional
player who has been overseeing the Japan Shogi Association’s mobile business as its mobile chief
editor, said that professional players were able to win the 2015 Den-osen matches because they
“had recognized the strength of software programs and made mental preparations to deal with it.”
Sato said that computer programs had begun playing “impressive shogi” in recent years. He said
that he had had absolutely no interest in playing shogi against the programs before, but that he had
recently started to think that competition with the programs that play shogi so well might help him
to improve his shogi skills and find the best move in each position.
Sato also said the following to me on our way back from Odawara Castle, where we witnessed
Morishita’s Den-osen loss to Tsutsukana. “Tsutsukana played shogi impressively well today. But
looking at the order of the moves it made, I felt that Tsutsukana played the game in a very narrow
way.” Unable to understand exactly what he meant, I asked him what the narrow way of playing
shogi was. In reply, Sato said, “It’s hard to explain, but the way Tsutsukana played was a risky way
of playing shogi, which has only one correct path outside of which everything else fails.” In spite of
this, computer programs are winning. Isn’t it OK for the programs to play shogi in whatever way
they choose as long as the chosen way leads to victories? In response to this second question, Sato
said, “Well, it’s the course, it’s a way of playing that humans never choose.” I did not understand
what Sato truly meant by those words at that point.
What Is the Best Move in the True Sense of the Word? – Is It Possible for Humans to Live Symbiotically with Computers?
Several months later, I had dinner with Sato one evening. After our dinner, I drove him to his house.
The car navigation system in my car instructed me to make a right at the next intersection when
we reached a neighborhood close to his house. But Sato told me to go straight ahead, instead of
turning right there, because that was the correct route. The car navigation system repeated the
instruction to turn right as we moved closer to the following two intersections. Sato kept telling me
to drive straight ahead, though. “Sato-sensei, what on earth will happen if I make rights?” In
response to my question, Sato said, “We can certainly reach my house by turning right at those
crossroads. It may even be a quicker route. But the roads on the way are winding or narrow, and
are difficult to travel down. It’s a route that we want to avoid under normal conditions. Machines
seem to have no consideration for such things.”
At that point, what Sato had said to me in Odawara flashed back into my head out of the blue.
Discuss Japan—Japan Foreign Policy Forum No. 32
“Sensei, you told me in Odawara that computer programs play shogi in a narrow way,” I said to
him to seek his confirmation. “Do you remember that? Did you mean something like this? We will
certainly reach your house by following what the car navigation system tells us. We will reach it
more quickly that way than by driving straight ahead. But that would be a choice that is too risky
for humans to take in view of the possibility of human error. When seeking victories in shogi,
computer programs nonchalantly make choices with great risks that humans would not make. They
do so because machines make no human error. Humans don’t imitate such choices. They should
not do so. Sensei, is my understanding correct?”
Sato remained silent for a while. He seemed to be giving some thought to the point I had just
raised. He then said, “You may be right.” Continuing, Sato said, “I think the point is what is best in
the true sense of the word. I have always thought that finding the best move is the job of shogi
professionals. I think discovering that is different from just finding a way to win matches. I think
it will be interesting if professional shogi players join forces with computer programs in the future
to discover what is best.”
Humans may become able to unravel truths and the best moves in shogi, which have been
invisible, by competing and joining forces with computer programs. A wide spectrum of
professional shogi players and the researchers and developers of computer shogi programs share
this way of thinking that Takeuchi and Sato have mentioned. Many of them appear to think that
humans and computers can live symbiotically by respecting each other and taking advantage of
each other’s strong points. It will be impossible to arrest the development of AI in the future world.
The author thought that the attitude of seeking symbiotic coexistence would be essential for
preventing a course toward a future where humans are not needed.
The Japan Shogi Association completed the Den-osen series of five matches between humans
and computer programs with the Den-osen Final series in 2015, and launched a new Den-osen
series in which the winners of separate tournaments for professional players and computer
programs play a championship match. Shogi is likely to continue attracting keen interest in Japan
as a test ground for human-AI coexistence.
Translated from an original article in Japanese written for Discuss Japan. [March 2016]
Note: This article was written by the author with the cooperation of the professional Shogi player
Sato Yasumitsu and the Japan Shogi Association.
KAMIYA Matake
Born in 1961, he graduated from the University of Tokyo and Graduate School of Arts and Sciences,
Columbia University (as a Fulbright Grantee), and is a Professor of International Relations at the
National Defense Academy of Japan. He is also a member of the board of directors of the Japan
Discuss Japan—Japan Foreign Policy Forum No. 32
Association for International Security, and a visiting superior research fellow at the Japan Forum
on International Relations. He is the co-editor of Introduction to Security Studies, 4th edition
(Chinese translation published by World Knowledge Publishing House in Beijing), and has
published extensively on East Asian security, Japanese foreign and security policy, Japan’s postwar
pacifism, U.S.-Japan security relations, and nuclear topics. He has been Editor-in Chief of Discuss
Japan since 2013.
SATO Yasumitsu
Born in 1969. He became a professional shogi player in 1987, at the age of 17, since when he has
won thirteen major tournaments, the seventh largest number in history. He is presently the
chairman of the Professional Shogi Players Association of the Japan Shogi Association.